1. Technical Field of the Invention
The present invention relates to a mobile telecommunications network and, in particular, to the transmission of short message service (SMS) messages using Intelligent Network (IN) services.
2. Description of Related Art
With the continuing developments of telecommunications technology, the concepts of an intelligent network (IN) and associated services have been developed to provide intelligent and advanced telecommunications services to subscribers. The basic concept behind IN is to move the "intelligence" out of each local exchange or Service Switching Point (SSP) and to centralize the services providing the intelligence in a Service Control Point (SCP). By centralizing the special subscriber services in an SCP, a new service can be added in only one place (the SCP) and provided to all subscribers connected to the multiple SSPs which are connected to the SCP. Consequently, a large number of subscribers connected by way of multiple SSPs are serviced by a single SCP.
Initially, IN was a concept implemented only within a Public Switched Telephone Network (PSTN) servicing wireline telecommunications subscribers. Accordingly, SSPs or local exchanges (LEs) communicated connection-less Signaling Control Connection Part (SCCP) based signals with an associated SCP to provide services to associated wireline subscribers. With the introduction of digital mobile telecommunications networks, such as a Global System For Mobile (GSM) based Public Land Mobile Network (PLMN), the IN technology is also being implemented in a wireless telecommunications environment. Accordingly, a mobile switching center (MSC) within a PLMN communicates with an associated Intelligent Network to provide IN services to associated mobile subscribers.
One IN service comprises a Private Number Plan (PNP) feature. A number of mobile subscribers are associated with each other, and each of the associated mobile subscribers is then identified by a short number (or more commonly known as extension numbers). As a result, those associated mobile stations function similar to Private Branch Exchange (PBX) subscribers, and one mobile subscriber may establish a call connection with another associated mobile subscriber by merely dialing the associated short number. Other such IN services include Originating Call Barring, Closed User Groups, Restriction Override, and Call Diversion.
With the introduction of GSM digital based telecommunications systems, a number of advanced non-speech services are further provided to mobile subscribers. One such service comprises a Short Message Service (SMS) . Using an SMS message, a mobile subscriber is able to communicate text messages with another mobile station or SMS terminals without establishing a call connection therebetween. A first mobile subscriber simply types the desired text message, indicates the directory number associated with the destination mobile subscriber, and transmits the SMS message encapsulating the desired text message.
However, one deficiency or inefficiency with the existing system is that the serving telecommunications network utilizes a first network to provide IN services and a second network to communicate SMS messages. As a result, even if a mobile subscriber has the PNP feature, the mobile subscriber is not currently able to transmit an SMS message to another associated mobile subscriber utilizing the associated short number. As a further illustration, even if the mobile subscriber has the Originating Call Barring feature to bar an outgoing call connection towards a particular destination number, the mobile telecommunications network is not able to bar an outgoing SMS message toward the same number. This is because, currently, a mobile telecommunications network for routing SMS messages does not interface with an associated IN.
Accordingly, there is a need for a mechanism to enable SMS messages to access existing IN services within a mobile telecommunications network.